Method of fluffing a wet fleece of staple fiber and a device for carrying out same



June 30, 1959 H. THIELE 2,892,219

METHOD OF FLUFFING A wET FLEECE OF STAPLE FIBER AND A DEVICE FORCARRYING OUT SAME Filed D80. 1, 1954 2 Sheets-Sheet l i v INVENTOR.

HANS THIELE BY MK H g-g,

ATTORNEY June 30, 1959 H. THIELE' METHOD OF FLUFF ING A WET FLEECE OFSTAPLE FIBER AND A DEVICE FOR CARRYING OUT SAME 2 Sheets-Sheet 2 FiledDec. 1, 1954 INV ENTOR.

nit Stats 2892319 Mnrnon or FLUFFENG A WET FLEECE or STAPLE FIBER AND ADEVICE FOR CARRY- ]NG OUT SAME Hans Thiele, Kassel, Germany, assignor toSpinnfaser Aktiengesellschaft, Kassel-Bettenhaiisen, Germany, a Germancorporation 7 Application December 1, 1954, Serial No. 472,454 Claimspriority, application Germany beceinber 9, 195 3 15 Claims. (Cl. 19- 65)The present invention relates to a method of opening a wet fleece or matof synthetic staple fiber in continuous operation and to a device forcarrying out the method of the invention.

After being washed, the fleece is conducted through squeezing rollerswhich appreciably reduce the moisture content of the fleece. The finaldrying is carried out in an air drying device in which hot air isdirected upon and through the moving fleece. This hot air serves toreduce the moisture content of the fleece. to a very low percentage.

When the fleece has passed the squeezing rollers, the individual fibersof the fleece are very strongly matted or felted. The bottom side of thefleece is particularly dense; it often has a somewhat leathery surface.As a result, the hot air current of the subsequent air drier cannotreadily penetrate into the interior of the fleece so that a substantialtime is required until the fleece is thoroughly dried. This necessitateslarge'sized air driers whereby the costs of the installation and theoperational costs are materially increased.

Various attempts have been made to provide means for mechanicallyloosening the coherent and strongly felted wet fleece prior to theintroduction thereof into the air drier to facilitate the penetration ofthe hot drying air.

One of the known means resides in conveying fleece layers of varyingthickness to the hot air drier on a conveyor bearing needle combs. Abovethis conveyor distributing rakes or combs are. mounted which are drivenby eccentrically mounted levers and which serve further to loosen theupper side of the already broken-up or loosened fleece so that thefleece has an approximately uniform thickness when reaching the airdrier. These aforedescribed means have serious disadvantages. Theindividual fibers are pulled out of the fiber material and likely to bedamaged by tearing. Furthermore, small fiber knots or nodes are formedin the fleece when the same is pulled forward in wet condition by therakes or combs. These fiber knots cannot be dissolved during thesubsequent treatment. The results are irregularities in the form ofknubs and burls in the yarn or fabric spun from the fibers. Furthermore,due to the swelling of the fibers when being wet, flat cakes tend to beformed which cannot be dissolved without difficulty after drying. Staplefiber thus deteriorated makes a lifeless impression.

Another method of opening or loosening the fiber fleece prior to thefinal drying resides in passing the fleece through a bending, kneading,rubbing or compressing device in which the fleece is subjected tovarious mechanical' operations and stresses working the fleece material.One of the best known devices of this type comprises meshed pairs ofgears which force the fleece, when passed between the same, intoa zigzagform whereby the fleece is kneaded and softened. However, devices ofthis kind have not been found to be satisfactory as the small flat cakeareas of the fleece cannot be dissolved by the same. The combinedapplication of the aforedescribcd mechan- 2,392,219 Patented June 30,1959 ical operations, namely bending, rubbing transversely to thedirection of travel and the alternating upsetting or compressing in thedirection of travel were alsofound not to be capable of suflicientlyopening. or loosening the wet fleece. In addition, the mechanicalworking as described has the disadvantage that as a result of the strongmechanical stresses to which the fleece material is subjected theindividual fibers of the fleece are frequently and extensivelydan'iaged.

Further attempts have been made to vibrate the fleece by suitablevibrators oi oscillators and to subject it transversely to its directionof travel to vibrations tending to divide the fleece in flat cake likeparts. However, the formation of flat cakes is undesirable as alreadymentioned. Furthermore, the surface fibers of the fleece which come indirect contact with the vibrator are often appreciably damaged by thefriction between said fibers and the respective parts of the vibrator.

Finally, methods and devices are known which employ pulsating aircurrents. travelling through the device is subjected on both sides firstto an excess atmospheric pressure and then to a subatmospheric pressure.It has also been proposed to subject one side of the fiber band toexcess atmospheric pressure and the other side to sub-atmosphericpressure. As a result, the fleece travels through the devicesubstantially along a sine line. However, the action of a deviceemploying only a pressure differential is not sufiicient since theindividual fibers of the fleece are frequently coherent to such anextent that the air cannot penetrate at all into the interior of thefleece.

One object of the present invention is to provide a novel and improvedmethod of opening and flufiing a wet fleece or mat of synthetic staplefiber without appreciably damaging the individual fibers forming thefleece or mat.

Another object of the invention is to provide a novel and improvedmethod of opening and flufling the wet fleece or mat by which the fleeceor mat is so thoroughly loosened that only a comparatively short time isrequired for completing the final drying operation in a hot air drier.

Still another object of the invention is to provide a novel and improvedmethod by which a highly uniform and flufiy fleece or mat is obtainablethereby greatly facilitating and expediting the subsequent operations tobe performed on the fleece or mat, or more specifically on the fibersthereof.

The aforementioned and other advantages are attained by subjecting themoving wetfleece or mat simultaneously to a purely mechanical bendingoperation and the action of air pressure. The combined simultaneousaction of the bending operation and the air pressure affords: theadvantage that the air can deeply penetrate into scale like fissuresformed in the fleece or mat by the bending operation thereby causing arapid and thorough flufiing of the fibers.

The advantageous eflect of'the combined bending and air pressure actionis further increased according to the invention, by supporting thefleece hollow upon or spaced apart from a solid support. permits the airfully to penetrate the fleece so that the fibers of the same areloosened both, in the direction toward the support and away from thesame.

The result is a completely loose and fluffy fleece or mat, the fibers ofwhich can be readily and thoroughly penetrated by the hot air of thedrier into which the fleece or mat is subsequently guided. Furthermore,the fibers are not damaged duringthe opening or fluffing operation sincethey are not subjected to any mechanical action by rakes, combs,beaters, vibrators etc. as heretofore used for opening the fleece.Moreover, the individual fibers substantially retain their initialposition In such devices, the fiber band Such spacing of the fleece' andlength which facilitates the subsequent operations.

Other and further objects, features and advantages of the invention willbe pointed out hereinafter and set forth in the appended claims formingpart of the application.

In the accompanying drawing a preferred embodiment of the inventionsuitable for carrying out the method of the invention is shown by way ofillustration and not by way of limitation.

Fig. 1 is a diagrammatic elevational view of a fleece working deviceaccording to the invention disposed between fleece squeezing rolls and ahot air drier.

Fig. 2 is a detail view of the device on an enlarged scale.

Fig. 3 is a further enlarged detail view to show the effect of the flowof pressure air upon'the fleece.

Fig. 4 shows a modification of the spikes supporting the fleece.

Fig. 5 shows a fleece supporting spike roller on which the spikes aredisposed in circumferential rows.

Fig. 6 shows a fleece supporting spike roller on which the spikes aredisposed in staggered relationship, and

Fig. 7 is a perspective view of a spike roller supporting the fleece andof a bank of nozzles directing a flow of pressure air upon the fleece.

A fleece 1 made of synthetic staple fiber after leaving a washing deviceis passed between two squeezing rollers 2 and 3 which serve to reducethe moisture content of the fleece. An upwardly slanted endless conveyor4 guides the fleece over a roller 5 of small diameter to a rotary spikeroller 6. Roller 6 carries a plurality of spikes. These spikes may beslender frusto-conical spikes as shown in Fig. 3 or slender conicalspikes 10:: as shown in Fig. 4. They may be arranged in circumferentialrows according to Fig. 5 or in staggered relationship according to Fig.6. Opposite to roller 6 and above the level of its rotational axis,nozzles 7 are provided communicating with a feed pipe 8 for pressureair. Fig. 7 shows a bank or row of nozzles 7 supplied with pressure airthrough the common feedpipe 8. The nozzles are so disposed that theydirect an air current against the fleece which impinges secantially uponthe fleece when and while the same is passing over roller 6. Afterpassing roller 6, the loosened or flulfed fleece is guided into a dryingdevice 9 in which the fleece is further and finally dried by hot air.

The spike roller 6 may be in form of a hollow cylinder havingperforations 11 distributed over its entire circurnference. Theseperforations serve to suck off air. To limit the perforated area throughwhich air can be sucked off, a suction pipe 12 may be provided withinthe cylinder which permits the influx of the outer air through theperforations 11 only through a pipe slot 13.

The device as hereinbefore described, operates as follows:

The fleece is delivered densely felted fiber mass.

to the device in form of a wet It is first guided by conveyor 4 to smallroller 5 and is comparatively sharply bent when passing under thisroller whereby the outer fibers of the fleece lying on the side thereofopposite to roller 5 are slightly pulled apart or spread. During itstravel from roller 5 to spike roller 6 the fleece is straightened butbent again and in opposite direction as before while being guided overroller 6, the diameter of which is also comparatively small. The spikesof roller 6 more specifically the tips thereof are so dimensioned thatthey cannot deeply penetrate into the fleece. Frusto-conical spikes havebeen found suitable. While the fleece is passing over roller 6 and isbeing bent in said opposite direction, the fibers on the side of thefleece which were on the inside when and while the fleece was passingover roller 5 are now lying on the outside of the fleece. As a result,these surface fibers are also pulled apart so that scale-like fissuresare formed in the fleece surface as can best be seen in Fig. 3 withoutsubjecting the fleece to appreciable mechanical stresses. The pressureair directed by nozzles 7 upon the bent outside of the fleece insecantial direction can hence deeply penetrate into the scale-likefissures formed in the fleece. The air current opens irregular channelswithin the fleece in the direction of movement of the fleece and at anangle thereto. A small portion of the air breaks through the sides ofthe fleece which is supported on the spikes, aided by the fissures onthis side and the suction. But the major portion of the air remains inthe loosened and flufled fleece thereby facilitating the subsequentdrying operation. As is evident, it is advantageous for theaforedescribed action of the air current that the fleece is supportedspaced apart from the body properv of roller 6 which is effected by theprovision of the spikes particularly of spikes of frusto-conical ortruncated shape. It is further evident that by the formation of fissureson both sides of the fleece effected by bending the fleece in oppositedirections the flufling of the fleece is materially increased. If thecircumferential speed of the spikes is substantially equal to the rateof movement of the fleece, practically no force has to be transmittedfrom the spikes to the fleece. Accordingly, there is hardly any tendencyfor the spikes to penetrate into the fleece as the same presses upon thespikes substantially with its own weight only. As explained, the aircurrent in coaction with the suction cause a loosening of the fleece inboth directions, that is, toward roller 6 and also away from the same sothat the fleece is thoroughly flufled as indicated in Fig. 2. The resultis that the wet fibers of the fleece tending to adhere to each other areseparated to a very large extent and that consequently the hot airwithin drier 9 can penetrate the fleece and fully and quickly dry thesame.

The pressure air delivered by nozzles 7 and penetrating the fleece canbe conducted away by the suction means previously described. However, itis advantageous that these suction means are effective only within therange of the angle at which the pressure air impinges upon the fleece.

To increase the scaling or splitting effect of spike roller 6, it isadvantageous, particularly for the treatment of heavier fleeces, toselect the circumferential speed of roller 6 slightly higher than themoving speed of the fleece imparted to it by conveyor 4. Suchdifferential speed assures that the outer fibers pulled apart andloosened by the action of roller 5 are not again compressed andflattened by roller 6. In the event that such differential speed isemployed, a certain force is trans mitted from the roller to the fleece.As a result, the spikes may slightly penetrate into the fleece, but thispenetration is not suflicient adversely to affect the operation of thedevice.

The bending of the fleece and the simultaneous application of pressureair generally result in a suflicient loosening and flufling of theindividual fibers of the Wet fleece to obtain a satisfactory furtherdrying. In the event that the action of a single device as hereinbeforedescribed, is not adequate several devices according to the inventionmay be provided in series arrangement.

The action of the device or devices according to the invention not onlyreduces the drying time required in the drier but also results in a moreuniform and fluflier fleece made of synthetic staple fiber.

While the invention has been described in detail with respect to acertain now preferred example and embodiment of the invention it will beunderstood by those skilled in the art after understanding theinvention, that various changes and modifications may be made withoutdeparting from the spirit and scope of the invention, and it isintended, therefore, to cover all such changes and modifications in theappended claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. The method of flufling but retaining in fleece form h indving wetfleece of felted synthetic staple fiber in continuous operation, whichcomprises the steps of bending and floatingly supporting successiveportions of the moving fleece for opening fissures in the bent fleeceportions and simultaneously directing an air current under pressure insecantial direction upon successive bent floatingly supported andfissured fleece portions.

2. The method of flufling but retaining in fleece form a moving wetfleece of felted synthetic staple fiber in continuous operation, whichcomprises the steps of subjecting successive portions of the movingfleece to successive bendings in opposite direction for opening fissureson both sides of the fleece, floatingly supporting the successiveportions when bent in one of said directions, and simultaneouslydirecting an air current under pressure in secantial direction uponsuccessive and floatingly supported bent fleece portions on the curvedside thereof opposite the center of the respective bending.

3. In the method according to claim 2, the additional step of subjectingthe floatingly supported fleece portions to a suction on the sidethereof opposite to the one to which said air under pressure is applied.

4. A device for flufiing but retaining in fleece form a moving wetfleece of felted synthetic staple fiber in continuous operation, saiddevice comprising a rotary bending means for bending the moving fleeceto open fissures in the side thereof opposite said bending means,peripheral support elements on said bending means for floatinglysupporting successive fleece portions, conveyor means for conveying thefleece to be flufled to said bending means, the peripheral speed of saidbending means being slightly in excess of the travelling speed of saidconveyor means, and air blower means disposed opposite said bendingmeans for directing an air current under pressure in secantial directionupon the fissured side of successive bent fleece portions when and whilethe same are supported by said support elements.

5. A device for flufling but retaining in fleece form a moving wetfleece of felted synthetic staple fiber in continuous operation, saiddevice comprising a rotary bending means for bending the moving fleece,said bending means including radially extending support elementssupporting spaced apart limited areas of the fleece to provide freespace on both sides of the fleece while the same is passing over saidbending means, and air blower means including air nozzles disposedopposite said bending means and oriented to direct a jet stream ofpressure air in secantial direction upon the fissured side of the fleecefacing the air nozzles while and when the fleece is supported on saidsupport elements.

6. A device according to claim 5, wherein the said rotary bending meanscomprise a spike roller supporting and guiding the fleece radiallyspaced from the body of the roller.

7. A device according to claim 6, wherein the spikes on said spikeroller are disposed in rows.

8. A device according to claim 6, wherein the spikes on said spikeroller are disposed on and distributed over the circumference of theroller in staggered relationship.

9. A device according to claim 5, wherein the said rotary bending meanscomprise a spike roller supporting and guiding the fleece radiallyspaced from the body of the roller, the spikes on said roller having aslender conical shape.

10. A device according to claim 5, wherein the said rotary bending meanscomprise a spike roller supporting and guiding the fleece radiallyspaced from the body of the roller, the spikes on said roller having aslender frustoconical shape.

11. A device according to claim 5, wherein the said rotary bending meanscomprise a hollow cylinder and a plurality of spikes radially extendingfrom the outer cylinder wall for supporting and guiding the fleeceradially spaced apart from said cylinder wall, the cylinder wallincluding a perforated Wall portion situated in the area in which saidsecantial jet stream impinges upon the cylinder wall, and suction meansfor sucking air from the interior of the cylinder entering the latterthrough said perforations.

12. A device for flufling but retaining in fleece form a moving wetfleece of felted staple fiber, comprising bending means for bending themoving fleece to open fissures in the side of the fleece opposite saidbending means including supporting elements engaging and floatinglysupporting the fleece at spaced apart limited areas to provide freespace on both sides of the fleece while being supported by saidsupporting elements, and air blower means disposed opposite to saidbending means for directing a current of air under pressure in secantialdirection upon the fissured side of successive bent fleece portions whenand while the same are supported by said supporting elements.

13. A device for flufling but retaining in fleece form a moving wetfleece of felted staple fiber in continuous operation, comprising firstbending means for bending the moving fleece to open fissures in the sideof the fleece opposite the said bending means, second bending meansdisposed posterior of the first bending means in the direction ofmovement of the fleece for bending the fleece in opposite direction toopen fissures in the other side of the fleece, said second bending meanshaving peripheral supporting elements engaging and floatingly supportingthe fleece at spaced apart limited areas to provide free space on bothsides of the fleece while being supported on said supporting elements,and air blower means disposed opposite to said second bending means fordirecting a current of air under pressure in secantial direction uponthe adjacent fissured side of successive bent fleece portions when andwhile the same are supported on said supporting elements.

14. A device according to claim 13, wherein said first bending meanscomprise a roller having a smooth peripheral surface, and wherein saidsecond bending means comprise a spike roller.

15. A device according to claim 14 and further comprising conveyor meansconveying the fleece to said smooth roller.

References Cited in the file of this patent UNITED STATES PATENTS720,298 Sullivan Feb. 10, 1903 1,485,410 Rackemann Mar. 4, 19242,136,506 Horn Nov. 15, 1938 2,139,445 Dinwiddle Dec. 6, 1938 2,532,330Ramsdell Dec. 5, 1950 2,589,008 Lannan Mar. 11, 1952 FOREIGN PATENTS26,216 Great Britain of 1912

